Method and apparatus for making plate-like fiber-reinforced products

ABSTRACT

A method for making a plate-like fibre-reinforced product to be used as building or packing material, the method comprising: placing fibres on a lower laminate; applying a binding agent on the fibres so that the fibres are surrounded by the binding agent; transferring the fibres with binding agent between the lower laminate and an upper laminate between lower and upper rotating pressing plates ( 4, 3 ); allowing the binding agent to foam up, expand and harden between the upper and lower pressing plates. In order to economically manufacture such a product with desired physical and mechanical properties, the method comprises the steps according to which the fibres are made into a three-dimensional cohesive fibre mat of fibres bound together, the fibre mat having a moisture content of 5% at the most before the binding agent is applied onto the fibre mat, the binding agent is applied onto the fibre mat and the obtained mixture is subjected to a pressure of at least 0.8 bar and 5 bar at the most and is allowed to harden to a plate-like product having a thickness of 10 to 150 mm; and the lower and upper laminate are removed from the hardening product. The invention also relates to a manufacturing apparatus and a plate-like product.

This is a U.S. national stage application of Application No.PCT/FI03/00442 filed Jun. 4, 2003. The entire disclosure of the priorapplication is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

The invention relates to a method and an apparatus for making aplate-like fibre-reinforced composite product to be used as building orpacking material. The invention also relates to a similar plate-likefibre reinforced composite product.

More particularly, the invention relates to a method for making aplate-like fibre-reinforced composite product to be used as building orpacking material, the method comprising: placing fibres on a lowerlaminate, applying a foaming hardening binding agent in liquid form onthe fibres so that the fibres are surrounded by the binding agent,transferring the fibres with binding agent between the lower laminateand an upper laminate between lower and upper pressing plates arrangedto rotate endlessly on the upper, respectively the lower, side of thefibres with the binding agent so that the fibres with the binding agentare transferred by means of the rotation speed of the pressing plates,and allowing the binding agent to foam up, expand and harden between theupper and lower pressing plates

More particularly, the present invention also relates to an apparatusfor making a plate-like fibre-reinforced composite product to be used asbuilding or packing material, the apparatus comprising an inlet end forreceiving fibres surrounded by binding agent, an outlet end forproviding the plate-like fibre-reinforced composite product manufacturedin the apparatus, an upper endlessly rotating belt comprising aplurality of upper pressing plates, which controlled by at least twoelongated control elements extending in the longitudinal direction ofthe apparatus are arranged to move on an upper endless track, and alower endlessly rotating belt comprising a plurality of lower pressingplates, which controlled by at least two elongated control elementsextending in the longitudinal direction of the apparatus are arranged tomove on a lower endless track, whereby the upper pressing plates withinan area of the upper endless track are arranged on a first substantiallyflat plane and the lower pressing plates within an area of the lowerendless track are arranged on a second substantially flat plane, whichis parallel to the first flat plane, whereby the upper and lowerpressing plates within the area are arranged to transfer the fibressurrounded by the binding agent between them, feed means for feeding anupper laminate and a lower laminate in said area, the upper laminate isarranged to be supported in said area against the upper pressing platesand to move at the same speed as the upper pressing plates, and thelower laminate is arranged to be supported in said area against thelower pressing plates and to move at the same speed as the lowerpressing plates,

More precisely, the present invention further relates to a plate-likefibre-reinforced composite product comprising fibres surrounded by abinding agent to be used as building or packing material.

Fibre-reinforced plate-like composite products to be used as building orpacking material are known in the art. They may be provided with aprotective cover, which in some cases simultaneously provide the productwith a more pleasant appearance.

The problem with known fibre-reinforced composite products is that themanufacture thereof is complicated. They are also easily affected bymoisture and variation in temperature, which may result in that the formof the products changes. The manufacturing methods, which are known inthis connection, require considerable capital investments as well as anextensive production volume. In addition, the final product, i.e. thefibre-reinforced composite product, is subjected to excessive moisturefluctuation. An example of a known method for making fibre-reinforcedcomposite products, such as chipboards, is the manufacture using adouble belt press. The double belt press is a huge apparatus in whichhigh-pressures, typically about 30 bar, and high temperatures, typicallyranging between 150 and 200 degrees Celsius, are used. The investmentcosts as well as the operating costs of such an apparatus areconsiderable. In addition, the apparatus requires a lot of space.

U.S. Pat. No. 5,089,189 discloses a method and an apparatus for makingplate-like composite products. The method and apparatus are complicatedand they do not allow manufacturing economically profitably a thickercomposite product that is suitable to be used as building or packingmaterial.

BRIEF DESCRIPTION OF THE INVENTION

It is an object of the present invention to provide a method and anapparatus, which allow reducing the costs for making fibre-reinforcedplate-like products so that manufacturing becomes economicallyprofitable for both large and small manufacturing volumes. The productshave typically been intended to be used within the building and packingindustry, and said products will be competing with competing products ofthe same use. Another object of the invention is to provide a productthat is in a stable form and that is advantageous to manufacture.

For this purpose, the method is characterized by the steps of: preparingthe fibres into a three-dimensional cohesive fibre mat of fibres boundtogether, the thickness of which basically ranges between 0.5 and 0.8 mmand the width between 0.3 and 2 mm, and the length of at least 80% ofthe fibres is at least 100 mm, before the binding agent is applied ontothe fibre mat, providing the fibre mat with a moisture content of 5% atthe most before the binding agent is applied onto the fibre mat,applying the binding agent onto the fibre mat so that a mixture of fibremat and binding agent is obtained, the mixture comprising fibres closeto the upper surface thereof, which is turned against the upper pressingplates, and close to the lower surface thereof, which is turned againstthe lower pressing plates, placing the mixture under a pressure of atleast 0.8 bar and 5 bar at the most and allowing the mixture to hardeninto a plate-like product having a thickness of 10 to 150 mm andcomprising fibres close to the upper surface thereof and close to thelower surface thereof when transferring the mixture between the pressingplates, and removing the lower and upper laminate from the hardeningproduct comprising fibres and binding agent.

The term fibre mat refers in this context principally to a structuremade of one or more fibres that is composed of one or more fibre layers,each one of which may suitably be in the form of a three-dimensionalfibre mat. If the fibre mat comprises more of such layers/mats, which istypical when thicker products are being manufactured (products having athickness over approximately 60 mm), the layers are placed so that thefinished final product comprises a layer close to both surfaces of thefinal product. The layers that are used in thick products (with athickness over approximately 60 mm) need not be of the same density.Besides, a layer of lower density may be provided between the layersthat are close to the surfaces of the product placed against oneanother.

The fibre mat is preferably prepared of hydroscopic fibres. The fibresmay be natural fibres or synthetic fibres. Preferably, the moisturecontent of the fibres is 8% at the most and the finished fibre mat istreated so as to obtain a moisture content of 3% at the most beforeapplying the binding agent. The fibre mat should be provided with acertain, relatively low moistness, when binding agent, for instancepolyurethane, is applied onto the fibres. Consequently, the bindingagent is firmly attached to the fibres, which is important in view ofthe physical properties of the final product, such as strength.

A final product with good physical properties is obtained when the fibremat is being prepared of fibres that mainly have a thickness of 0.5 to0.8 mm and a width of 0.3 to 2 mm, whereby the length of at least 80% ofthe fibres is at least 100 mm. Wood fibres are appropriate to be usedand the binding agent may preferably be polyurethane, whereby a productof stable form and good insulation properties is obtained.

The final product is provided with the desired density and strength byexposing the mixture of fibres and binding agent, when the binding agentfoams up, under a pressure of 1 to 2 bar at the most when the mixture istransferred between the pressing plates.

The preferred embodiments of the method are disclosed in the appendedclaims 2 to 11.

The apparatus according to the invention is characterized by comprisingpressing means for creating a pressure of at least 0.8 bar towards thepressing plates, and heating means for heating the mixture of fibres andbinding agent and by the upper pressing plates of the apparatus beingarranged at a distance of 10 to 150 mm from the lower pressing plates.

The first substantially flat plane and the second substantially flatplane, which are determined by the upper, respectively the lower,supporting elements, need not be exactly parallel, but may form a smallangle of for instance 1 to 5 degrees.

The apparatus may be referred to as a double belt conveyor or alaminator. Double belt conveyors/laminators that deviate from thepresent apparatus and that should be used for other purposes are alreadyknown in the art. The present invention therefore comprises the use of adouble belt conveyor/laminator for manufacturing plate-likefibre-reinforced composite products.

Consequently, the apparatus according to the invention is a laminatorthat deviates from prior art laminators by being especially built to beable to handle the pressure that it is subjected to when manufacturingthe plate-like product. Standard laminators used for manufacturingpolyurethane or sandwich panelling are unable to endure a pressure thatexceeds approximately 0.7 bar.

Preferably, the feed means and collecting means are arranged to transferthe upper and the lower laminate on respective endless racks. Acontinuously operating apparatus is thus obtained that is able toproduce several meters of plates by using only a small amount oflaminate that depending on the production volume may rotate a desirednumber of rounds on their respective endless tracks.

Said area within the apparatus, in which the plate is being made, inother words the area that extends from the inlet end to the outlet end,is preferably of a length that ranges between 5 and 30 m and a widththat ranges between 1 and 5 m.

Preferably, the apparatus comprises a number of spray nozzles, which areplaced to provide rapidly and evenly a desired amount of binding agenton the desired area of the lower laminate. The nozzles may be stationaryor alternatively arranged to move back and forth above the fibre mat.

Preferably, the apparatus comprises pressing means in the form ofcylinders. The cylinders allow providing the final product, before theproduct exits the apparatus, with a pressure of 0.8 bar, the pressureproviding a suitable density for the final product, when the bindingagent is polyurethane. Final products of desired size are obtained bycutting the product exiting the apparatus into desired sizes. A desiredthickness is obtained by adjusting the distance between the upper andlower pressing plates, for which purpose the pressing means of theapparatus are preferably arranged. The weight ratio between fibres andbinding agent in the final product may advantageously be 0.8 to 2corresponding to an amount of 45 to 67% fibres by weight in the finalproduct. A considerable weight ratio is aimed at (i.e. preferably closerto 2 than 0.8) in order to keep the manufacturing costs of the productlow, which may increase when the amount of binding agent increases. Theweight ratio may range between 0.1 and 4, i.e. the amount of wood fibrein the final product is 10 to 80%.

The most significant advantage of the method and apparatus according tothe invention is to allow manufacturing economically plate-likefibre-reinforced composite products of a stable form both in large andsmall production volumes, the products being suitable to be used asbuilding or packing material. This is due to the fact that the capitalexpenses and operative expenses of the apparatus are low in comparisonwith for instance the use of a double belt conveyor, and that a fibremat is included in the product. When the production volume remains low,the production need not take place around the clock.

The plate-like fibre-reinforced composite product according to theinvention is characterized in that the thickness of the plate-likeproduct is 10 to 150 mm, the form of the fibres resemble athree-dimensional cohesive mat, in which the fibres are surrounded bybinding agent, that the thickness of the fibres mainly ranges between0.5 and 0.8 mm and the width between 0.3 and 2 mm, and the length of atleast 80% of the fibres is at least 100 mm, that the composite productcomprises fibres close to the upper and lower surface, and in that theweight ratio between fibres and binding agent ranges between 0.1 and 4.Preferably, the fibre mat extends from the lower surface to the uppersurface of the product. Consequently, some of the fibres extend from thelower surface up until the upper surface.

The most significant advantages of the composite product are that theform of product is stable, which is particularly important for buildingmaterials within the building industry, the product comprises a goodstrength/density ratio, and the manufacturing costs thereof remain low.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in more detail in theaccompanying drawing, in which

FIG. 1 is a side view showing a sketch of an apparatus,

FIG. 2 is a top view illustrating the apparatus in FIG. 1,

FIG. 3 shows the apparatus shown in FIG. 2 according to the cutting lineIII-III,

FIG. 4 shows a detail of the apparatus shown in FIGS. 1 to 3,

FIG. 5 illustrates a product according to the invention, and

FIG. 6 schematically shows a method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an apparatus for continuously making plate-likefibre-reinforced composite products, which comprise a fibre componentand a binding agent. The binding agent may eventually be referred to asfiller. The fibre component is composed of a fibre mat of for instancewood wool and the binding agent is for instance polyurethane, which isallowed to foam up in the apparatus so that it hardens arid comprisesgas cells. A product including such component parts is provided withgood qualities if used as a building material, where an appropriateinsulating property is required, a particular strength and measurestability under various conditions. The product can also be used forpacking and eventually for other purposes. Instead of fibres based onwood and cellulose, the fibre component may basically include any fibresthat allow the product to be provided with a desired strength increasein comparison with a situation in which the final product lacks thefibre component. Thus, the fibre component can for instance be made offibreglass. Metal fibre can also be employed. In addition topolyurethane, the binding agent may be a phenol-based material.

Regardless of which binding agent is used, the fibres are embedded inthe binding agent. Thus, the binding agent is fastened to the fibres sothat the fibres provide a desired increase for the strength of the finalproduct. One of the good qualities of polyurethane is that it typicallyhas an extensive fastening ability.

The apparatus shown in FIG. 1 comprises an upper endless belt, band ortrack 1 and a lower endless belt, band or track 2. Both sides of thetracks are provided with side covers 26 to 29, cf. FIG. 3. The sidecovers 26 to 29 are not shown in FIG. 1 in order to better illustratethe inner parts of the apparatus. The side covers 26 to 29 are notnecessary.

The upper track 1 comprises a plurality of pressing shoes or pressingplates 3, which can be referred to as upper pressing plates. The numberof pressing plates 3 depends on the length of the apparatus; the numbercan for instance range between 20 and 200. The lower track 2 comprises aplurality of pressing plates 4, which can be referred to as lowerpressing plates. The number of the lower pressing plates 4 correspondsto the number of upper pressing plates 3, but may be somewhat higher,since a support from above for the fibre mat and binding agent need notnecessarily be placed in the vicinity of an inlet end 10. The pressingplates 3, 4 that are made of metal, such as steel or aluminum, rotatearound respective cogwheels 5, 6 and 7, 8, which are driven by means ofa drive motor 39 The control cabin of the apparatus is indicated withreference numeral 40. The area around the cogwheels 5 and 7 is the inletend 10 of the apparatus, and the area around the cogwheels 6 and 8 is anoutlet end of the apparatus.

In the area extending between the cogwheels 5 and 6, 7 and 8respectively, i.e. between the inlet end 10 and the outlet end 11, thetracks 1 and 2 are substantially flat. The length of this area istypically 5 to 30 m, whereby the area from 10 to 20 m covers most of theproduction needs. The greater the length, the higher the operating speedof the apparatus becomes. Conveying speeds between 2 and 15 meters perminute are typically used in the apparatus. The lower track 2 starts 2 mbefore the upper track 1 seen from the direction in which the mixture offibre mat and binding agent is transferred. However, said shift of thetrack is not shown in the drawing. The shift of the track allowsproviding the mixture of fibre mat and binding agent with a bettersupport before the mixture is inserted between the upper and the lowertrack.

In order for the tracks 1, 2 in said area not to bend and to obtain aform that deviates from a substantially flat form, for instance owing topressure that is formed when the binding agent foams up, the apparatuscomprises a number of cylinders 9, which together with the controlelements 32 keep the pressing plates 3, 4 of the apparatus flat in saidarea, cf. FIGS. 1 and 4. In FIG. 1, only two cylinders 9 have been shownfor the sake clarity, although several cylinders may be found along theapparatus. The cylinders 9 allow adjusting the distance between theupper and the lower track depending on the thickness of the product tobe manufactured. Instead of cylinders 9 other resistor/adjustingelements provided with the same functions can also be used. Both tracks1, 2 include three control elements 32, whereof one is centrally placedand two are placed on each side between the respective edges of thecontrol plates in the central control element, in which case thepressing plates 3, 4 may be relatively small and light without beingsubjected to bend when a pressure of 1 to 2 bar is placed upon them. Thecontrol elements 32 extending in the longitudinal direction of theapparatus can be referred to as rails. The pressing plates 3, 4 comprisegripping parts 38 that co-operate with the holes in respective conveyorchains 35 so that the gripping parts are inserted in the holes in orderto be transferred using the conveyor chains. The conveyor chains 35 arearranged to be supported by the control elements 32, cf. FIG. 4.

The distance between the upper band 1 and the lower band 2 in the areawhere the binding agent may foam up is typically 10 to 30 mm, but up to150 mm is possible when thick final products are being made. If thethickness of the final product is between 30 and 50 mm, said product mayadvantageously contain a fibre mat comprising a lower mat close to thelower surface of the final product and an upper mat close to the uppersurface of the final product. If the thickness of the final productexceeds 60 mm, it may advantageously contain a fibre mat comprisingthree mats so that two more dense mats are arranged close to the upper,respectively lower, surface of the final product and a lighter (thinner)mat is arranged between the more dense mats.

Reference numeral 12 indicates an upper laminate that may endlesslyrotate around the upper endless track 1. The laminate 12 is supported byfour rollers or cylinders 13 to 16, whereof one cylinder 13 is placedclose to the inlet end 10 of the apparatus and a second cylinder 14 isplaced close to the outlet end 11 of the apparatus. The lower side ofthe apparatus is correspondingly provided with a lower laminate 17,which supported by cylinders 18 to 21 is able to endlessly rotate aroundthe lower endless track 2. The Figure shows that the cylinder 18 islocated further from the inlet end 10 than the cylinder 13. This isconnected with the fact that binding agent should be applied onto thefibre mat before the fibre mat and binding agent arrive at the inlet end10.

The upper and the lower laminate 12, respectively 17, are preferablymade of polyethylene foil. A foil of some other material can beemployed, in which case the foil should be of such a material that thebinding agent (such as polyurethane) is not attached to the foil.Polytetrafluoroethylene (PTFE), or what is known as Teflon, is anexample of such a material.

In FIG. 1, reference numeral 22 indicates a conveyor by means of whichthe fibre mat 23 is fed onto the lower laminate 17 and towards the inletend 10 of the apparatus. In the area between the cylinders 18 and 13,the area being referred to as an application area, is provided with anumber of sprinklers or spray nozzles 24 by means of which binding agent25 is injected onto the lower laminate 17. The number of spray nozzles24 may vary: the greater the product and the higher the speed, thelarger the number of spray nozzles required in general. The number ofspray nozzles 24 may vary for instance between 3 and 100. The spraynozzles 24 can preferably be arranged to move back and forth in thetransverse direction in relation to the longitudinal direction of theapparatus, whereby the number of spray nozzles maybe small; it is alsopossible that the apparatus is provided with only a single spray nozzle.In the cylinder 13, the upper laminate 12 encounters the mixture offibre mat 23 and binding agent 25. It can be said that the upper and thelower laminate 12, respectively 17, provide the mixture with a kind ofform. Within the area between the inlet end 10 and the outlet end 11,the mixture of fibre mat and binding agent is allowed to foam up andharden so that a hardened flat product is provided at the outlet endthat is covered with laminate 12, 17 on both sides. The laminates 12, 17are removed at the cylinders 14 and 19. The laminates 12, 17 rotate onthe respective endless tracks by means of frictional force that is foundin the area between the inlet end 10 and the outlet end 11.Alternatively, it is possible that a drive cylinder makes the laminates12, 17 rotate, whereby one of the cylinders 13 to 16, respectively 18 to21 are driving.

FIG. 2 shows a top view of the apparatus. In FIG. 2, the upper laminate12 is not shown; and the cylinders 14 to 16 are illustrated with adashed line. The width of the pressing plates 3, 4 is 3 m, but the widthmay be greater, up to 5 m, if very broad products are to bemanufactured. The pressing plates 3, 4 may also be considerably smallerthan 3 m, but smaller than 1 m are not to be recommended.

FIG. 3 shows the apparatus in the longitudinal direction in crosssection of line III-III in FIG. 2. The Figure shows that the tracks 1, 2on both sides are provided with side covers 26 to 29.

FIG. 5 shows a plate-like fibre-reinforced composite product accordingto the invention. The Figure shows that the fibres extend from the lowersurface of the product to the upper surface thereof so that the fibresare found throughout the product. Some fibres go right through theproduct.

In the following with reference to FIG. 6, the method for making theplate-like fibre-reinforced composite products by means of the apparatusshown in FIGS. 1 to 3 is described in more detail.

Wood fibres having a thickness of 0.5 to 0.8 mm and a width of 0.3 to 2mm are manufactured. The fibres are dried so that the moisture contentthereof remains very low; the moisture content should not exceed 8%. Thelength of the fibres may vary between 8 and 250 mm. A three-dimensionalfibre mat 23 is prepared of such fibres, whereof preferably 80% are atleast 100 mm long. Such a mat is kept together during the entiremanufacturing process.

The fibre mat 23 is provided with moisture content of 3 to 4%. Thedesired moisture content is achieved with appropriate dryers/dampers. Ifthe moisture content exceeds said value, the final product remains poor.The moisture content should therefore exceed the value 0.5%. As it isnot technically difficult to achieve the last-mentioned moistureinterval, and as a person skilled in the art simply knows which type ofdryer/damper can be used, the structure of such a dryer/damper is notexplained in more detail herein.

The fibre mat 23 provided with a moisture content of 4% at the most orin some cases 5% at the most is made stable by binding together thefibres thereof. Binding together allows maintaining the fibres in thefibre mat together and the fibres are not spread apart in an undesirablemanner when applying the binding agent (polyurethane).

The fibre mat 23 is controlled by a speed of 7 meters per minute on thelower laminate 17 and polyurethane in liquid form is injected onto thefibre mat by means of the spray nozzles 24. The fibre mat 23 that issurrounded by polyurethane in liquid form is transferred towards thecylinder 13, in which the mixture is provided on the upper side thereofwith an upper laminate. The mixture of fibre mat and polyurethane isfound between the upper and lower laminate. It is possible in additionthereto to provide, if desired, the sides with additional stops, whichprevent the polyurethane from running out of the sides. This is normallynot necessary, since the polyurethane flows relatively slowly andhardens rapidly when conveyed in the apparatus.

The mixture of fibre mat 23 and polyurethane is transferred between theendless belts 1, 2 and is allowed to foam up and harden between them. Apressure of at least 0.8 bar and 2 bar at the most is applied onto themixture of fibre mat and polyurethane within the area between the belts1, 2. No particular pressure should be provided at the inlet end 10, butespecially in the latter half of the apparatus, i.e. in the part of theapparatus that is placed between the outlet end 11 and the middle of theapparatus, the pressure of 1 to 2 bar should be on hand. Higherpressures are not required and would only be of disadvantage. When thepolyurethane foams up and hardens, the temperature is at least 30degrees Celsius between the belts 1, 2. Since the polyurethane undergoesan exothermic reaction, in other words generates heat when it foams up,the pressing plates are heated to avoid heat shocks using infraredradiation emitting heating lamps 30, 31, which are schematicallyindicated by a dashed line in FIG. 1. On account of the heating, thetemperature of the pressing plates does not differ too much from thetemperature of the foamed polyurethane, which ranges between 30 and 90degrees Celsius. Excessive differences in temperature may result in heatshocks providing a poorer product as a result. Heating of the pressingplates is typically required only when the apparatus is started; whenthe apparatus has been in motion for a while the pressing plates obtainan appropriate temperature, which is maintained with the temperaturethat the foamed-up polyurethane provides the pressing plates. Instead ofheating lamps arranged between the cogwheels 5, 6, other types ofheating arrangements can also be used. A temperature exceeding 100degrees Celsius should not be provided between the belts, since hightemperatures are only of disadvantage and would increase productioncosts. The laminates 12 and 17 are removed from the hardening productafter having exited the outlet end 11. Hereafter the sides are madestraight and the product is cut into a desired length. In the finalproduct, the weight ratio between fibres and binding agent rangesbetween 0.8 and 2, typically between 1 and 1.3. The foamed-uppolyurethane is provided with a density of 25 to 100 kg/m³.

For a product having a thickness of 10 mm, a fibre mat with a thicknessof 15 to 30 mm is used as a starting material. For a final producthaving a thickness of approximately 50 mm at the most, a fibre mat witha thickness of 70 to 150 mm is employed. If the thickness of the finalproduct is 100 mm, two fibre mats are used, which are provided with athickness of 70 to 150 mm each. If the thickness of the final product is150 mm, three fibre mats are preferably used having a thickness of 70 to150 mm each. In products, in which the fibre mat is composed of severallayers (fibre mats), it is possible during the manufacturing process ofthe final product to apply binding agent between the layers so as toachieve an appropriate adhesion.

The invention has above been described merely by means of examples andit is therefore pointed out that the details of the invention can beimplemented in various ways within the scope of the appended claims. Itis therefore possible to use for instance as starting material otherhygroscopic fibres than wood fibres. The advantage with wood fibres is,however, to provide a final product provided with good physical andmechanical properties; the production costs of such a product thusremaining very low. Instead of polyurethane, a phenol-based material canalso be employed. The conveying speed in the apparatus may also vary,whereby the speed typically ranges between 2 and 15 meters per minute.The dimensions of the final product may vary. The number of spraynozzles may vary: it is possible to use one or more nozzles, whichinstead of being stationary may be arranged to move in the transversedirection in relation to the direction, in which the fibre mat 23 moves.Another type of traversing spray arrangement than spray nozzles can alsobe used. Instead of spray nozzles 24, the fibre mat can be provided witha binding material through tubes or by pouring by means of one or moregrooves. Feed apparatuses for feeding and collecting the laminates 12,17 may vary in detail, for instance, so that a different number ofcylinders 13 to 16, 18 to 21 is used. The feed apparatuses need not bearranged to feed the laminate 12, 17 on a continuous track, althoughthis is to be recommended. Consequently, the laminates can alternativelybe collected.

1. A method for making a plate-like fiber-reinforced composite productto be used as building or packing material, the method comprising thesteps of preparing a three-dimensional cohesive fiber mat of fibersbound together, the fibers having a thickness mainly ranging between 0.5and 0.8 mm and a width between 0.3 and 2 mm, at least 80% of the fibershaving a length of at least 100 mm, providing the fiber mat with amoisture content of at or below 5%, placing the fiber mat on a lowerlaminate, applying a foaming hardening binding agent in liquid form onthe fibers of the fiber mat so that a mixture of fiber mat and bindingagent is obtained wherein the fibers are surrounded by the bindingagent, transferring and guiding the mixture between the lower laminateand an upper laminate between lower and upper pressing plates, saidlower and upper laminate and said pressing plates being arranged torotate endlessly at a rotation speed on an upper and, respectively alower, side of the mixture thereby transferring the mixture at therotation speed of the pressing plates, the mixture comprising fibersclose to an upper surface thereof and close to a lower surface thereof,placing the mixture under a pressure between about 0.8 bar and about 5bar and allowing the binding agent to foam up and expand and allowingthe mixture to harden between the upper and the lower pressing platesinto a hardened plate-like product having a thickness of 10 mm to 150 mmand comprising fibers close to the upper surface thereof and close tothe lower surface thereof when transferring the mixture between thepressing plates, and removing the laminates from the hardened product.2. A method as claimed in claim 1, wherein the fiber mat before applyingthe binding agent thereto has a thickness of approximately 1.5 to 3times the hardened product.
 3. A method as claimed in claim 1, whereinthe fiber mat is made of hygroscopic fibers.
 4. A method as claimed inclaim 1, wherein the foaming binding agent is applied onto a fiber mathaving a moisture content of less than about 3%.
 5. A method as claimedin claim 1, wherein the mixture of fibers and binding agent is subjectedto a pressure of less than about 2 bar.
 6. A method as claimed in claim1, wherein a material with a good adhesiveness is used as binding agent.7. A method as claimed in claim 4, wherein polyurethane is used as thebinding agent.
 8. A method as claimed in claim 6, wherein a phenol-basedmaterial is used as the binding agent.
 9. A method as claimed in claim1, wherein the fibers comprise wood fibers.
 10. A method as claimed inclaim 7, wherein the fiber mat including the polyurethane is transferredbetween the pressing plates at a temperature ranging between 30 and 90degrees Celsius.
 11. A method as claimed in claim 1, wherein the bindingagent is applied onto the fiber mat by spray nozzles.